function searchString() {
    var selectedList = document.forms["myForm"].elements["menu"];
    if (selectedList.selectedIndex == 2) {
        document.getElementById("flightNumber").style.display = "block";
    }
    else {
        document.getElementById("flightNumber").style.display = "none";
    }
    if ((selectedList.selectedIndex == 0) || (selectedList.selectedIndex == 1)) {
        document.getElementById("flightFromTo").style.display = "block";
    }
    else {
        document.getElementById("flightFromTo").style.display = "none";
    }
    if (selectedList.selectedIndex == 4) {
        document.getElementById("flightInput").style.display = "block";
    }
    else {
        document.getElementById("flightInput").style.display = "none";
    }
}

